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81.
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83.
Anisimov SV Christophersen NS Correia AS Hall VJ Sandelin I Li JY Brundin P 《Cellular & molecular biology letters》2011,16(1):79-88
The majority of human embryonic stem cell lines depend on a feeder cell layer for continuous growth in vitro, so that they can remain in an undifferentiated state. Limited knowledge is available concerning the molecular mechanisms
that underlie the capacity of feeder cells to support both the proliferation and pluripotency of these cells. Importantly,
feeder cells generally lose their capacity to support human embryonic stem cell proliferation in vitro following long-term culture. In this study, we performed large-scale gene expression profiles of human foreskin fibroblasts
during early, intermediate and late passages using a custom DNA microarray platform (NeuroStem 2.0 Chip). The microarray data
was validated using RT-PCR and virtual SAGE analysis. Our comparative gene expression study identified a limited number of
molecular targets potentially involved in the ability of human neonatal foreskin fibroblasts to serve as feeder cells for
human embryonic stem cell cultures. Among these, the C-KIT, leptin and pigment epithelium-derived factor (PEDF) genes were
the most interesting candidates. 相似文献
84.
Martínez-Sernández V Muiño L Perteguer MJ Gárate T Mezo M González-Warleta M Muro A Correia da Costa JM Romarís F Ubeira FM 《PLoS neglected tropical diseases》2011,5(11):e1376
Background
Human fasciolosis is a re-emerging disease worldwide and is caused by species of the genus Fasciola (F. hepatica and F. gigantica). Human fasciolosis can be diagnosed by classical coprological techniques, such as the Kato-Katz test, to reveal parasite eggs in faeces. However, although 100% specific, these methods are generally not adequate for detection of acute infections, ectopic infections, or infections with low number of parasites. In such cases immunological methods may be a good alternative and are recommended for use in major hospitals where trained personnel are available, although they are not usually implemented for individual testing.Methodology/Principal Findings
We have developed a new lateral flow test (SeroFluke) for the serodiagnosis of human fasciolosis. The new test was constructed with a recombinant cathepsin L1 from F. hepatica, and uses protein A and mAb MM3 as detector reagents in the test and control lines, respectively. In comparison with an ELISA test (MM3-SERO) the SeroFluke test showed maximal specificity and sensitivity and can be used with serum or whole blood samples.Conclusions/Significance
The new test can be used in major hospitals in hypoendemic countries as well as in endemic/hyperendemic regions where point-of-care testing is required. 相似文献85.
Batista Dda G Batista MM de Oliveira GM Britto CC Rodrigues AC Stephens CE Boykin DW Soeiro Mde N 《PloS one》2011,6(7):e22155
Chagas disease caused by Trypanosoma cruzi is an important cause of mortality and morbidity in Latin America but no vaccines or safe chemotherapeutic agents are available. Combined therapy is envisioned as an ideal approach since it may enhance efficacy by acting upon different cellular targets, may reduce toxicity and minimize the risk of drug resistance. Therefore, we investigated the activity of benznidazole (Bz) in combination with the diamidine prodrug DB289 and in combination with the arylimidamide DB766 upon T. cruzi infection in vivo. The oral treatment of T.cruzi-infected mice with DB289 and Benznidazole (Bz) alone reduced the number of circulating parasites compared with untreated mice by about 70% and 90%, respectively. However, the combination of these two compounds decreased the parasitemia by 99% and protected against animal mortality by 100%, but without providing a parasitological cure. When Bz (p.o) was combined with DB766 (via i.p. route), at least a 99.5% decrease in parasitemia levels was observed. DB766+Bz also provided 100% protection against mice mortality while Bz alone provided about 87% protection. This combined therapy also reduced the tissular lesions induced by T. cruzi infection: Bz alone reduced GPT and CK plasma levels by about 12% and 78% compared to untreated mice group, the combination of Bz with DB766 resulted in a reduction of GPT and CK plasma levels of 56% and 91%. Cure assessment through hemocultive and PCR approaches showed that Bz did not provide a parasitological cure, however, DB766 alone or associated with Bz cured ≥13% of surviving animals. 相似文献
86.
Eunice Areal Bacelar José M. Moutinho-Pereira Berta C. Gon?alves Jo?o I. Lopes Carlos M. Correia 《Acta Physiologiae Plantarum》2009,31(3):611-621
Gas exchange rates, chlorophyll fluorescence, pressure–volume relationships, photosynthetic pigments, total soluble sugars,
starch, soluble proteins and proline concentrations were investigated in five Olea europaea L. cultivars with different geographical origins (Arbequina, Blanqueta, Cobran?osa, Manzanilla and Negrinha) grown under
Mediterranean field conditions. We found considerable genotypic differences among the cultivars. Comparing the diurnal gas
exchange rates, we observed that Cobran?osa, Manzanilla and Negrinha had high photosynthetic rate than Arbequina and Blanqueta.
The first group reveals to be better acclimated to drought conditions, and appears to employ a prodigal water-use strategy,
whereas Blanqueta and Arbequina, with high water-use efficiency, appear to employ a conservative water-use strategy. The degree
of midday depression in photosynthesis was genotype dependent, with a maximum in Arbequina and a minimum in Negrinha. The
reductions in the photosynthetic rate were dependent from both stomatal and non-stomatal limitations. Elastic adjustment plays an important role as drought tolerance mechanism. The group of cultivars that employ a prodigal
water-use strategy revealed high tissue elasticity, whereas Arbequina and Blanqueta revealed high tissue rigidity. We also
identified the existence of drought tolerance mechanisms associated with soluble proteins accumulation in the foliage. The
high levels of soluble proteins in Arbequina may represent an increased activity of oxidative stress defence enzymes and may
also represent a reserve for post stress recovery. In all cultivars, especially in Manzanilla, free proline was accumulated
in the foliage. The discussed aspects of drought stress metabolism may have an adaptative meaning, supporting the hypothesis
that olive cultivars native to dry regions, such as Cobran?osa, Manzanilla and Negrinha, have more capability to acclimate
to drought conditions than cultivars originated in regions with a more temperate climate, like Arbequina and Blanqueta. 相似文献
87.
88.
Alves S Paulo A Correia JD Gano L Smith CJ Hoffman TJ Santos I 《Bioconjugate chemistry》2005,16(2):438-449
Radiolabeling of biologically active molecules with the [(99m)Tc(CO)(3)](+) unit has been of primary interest in recent years. With this in mind, we herein report symmetric (L(1)) and asymmetric (L(2)-L(5)) pyrazolyl-containing chelators that have been evaluated in radiochemical reactions with the synthon [(99m)Tc(H(2)O)(3)(CO)(3)](+) (1a). These reactions yielded the radioactive building blocks [(99m)Tc(CO)(3)(k(3)-L)](+) (L = L(1)-L(5), 2a-6a), which were identified by RP-HPLC. The corresponding Re surrogates (2-6) allowed for macroscopic identification of the radiochemical conjugates. Complexes 2a-6a, with log P(o/w) values ranging from -2.35 to 0.87, were obtained in yields of > or =90% using ligand concentrations in the 10(-5-)10(-4) M range. Challenge studies with cysteine and histidine revealed high stability for all of these radioactive complexes, and biodistribution studies in mice indicated a fast rate of blood clearance and high rate of total radioactivity excretion, occurring primarily through the renal-urinary pathway. Based on the framework of the asymmetric chelators, the novel bifunctional ligands 3,5-Me(2)-pz(CH(2))(2)N((CH(2))(3)COOH)(CH(2))(2)NH(2) (L(6)) and pz(CH(2))(2)N((CH(2))(3)COOH)(CH(2))(2)NH(2) (L(7)) have been synthesized and their coordination chemistry toward (NEt(4))(2)[ReBr(3)(CO)(3)] (1) has been explored. The resulting complexes, fac-[Re(CO)(3)(k(3)-L)]Br (L(6)(7), L(7)(8)), contain tridentate ancillary ligands that are coordinated to the metal center through the pyrazolyl and amine nitrogen atoms, as observed for the other related building blocks. L(6) and L(7) were coupled to a glycylglycine ethyl ester dipeptide, and the resulting functionalized ligands were used to prepare the model complexes fac-[Re(CO)(3)(kappa(3)-3,5-Me(2)-pz(CH(2))(2)N(glygly)(CH(2))(2)NH(2))](+) (9/9a) and fac-[Re(CO)(3)(kappa(3)-pz(CH(2))(2)N(CH(2))(3)(glygly)(CH(2))(2)NH(2))](+) (10/10a) (M = Re, (99m)Tc). These small conjugates have been fully characterized and are reported herein. On the basis of the in vitro/in vivo behavior of the model complexes (2a-6a, 9a, 10a), we chose to evaluate the in vitro/in vivo biological behavior of a new tumor-seeking Bombesin pyrazolyl conjugate, [(L(6))-G-G-G-Q-W-A-V-G-H-L-M-NH(2)], that has been labeled with the [(99m)Tc(CO)(3)](+) metal fragment. Stability, in vitro cell binding assays, and pharmacokinetics studies in normal mice are reported herein. 相似文献
89.
Pinheiro RO Pinto EF Lopes JR Guedes HL Fentanes RF Rossi-Bergmann B 《Microbes and infection / Institut Pasteur》2005,7(13):1317-1323
Leishmania amazonensis and Leishmania braziliensis are the main causal agents of anergic diffuse cutaneous leishmaniasis and hyperergic mucosal leishmaniasis in man, respectively. In this work we demonstrate that intramuscular vaccination of BALB/c mice with whole antigens of L. amazonensis (LaAg) but not L. braziliensis (LbAg) results in increased susceptibility to cutaneous leishmaniasis. LaAg vaccination resulted in an increased capacity of the draining lymph nodes to produce IL-10 and TGF-beta during antigen recall responses. In vitro cultivation with LaAg but not LbAg induced increased apoptosis of CD8+ T cells. Following infection with L. amazonensis, LaAg-vaccinated mice produced significantly more TGF-beta and a higher serum IgG1/IgG2a antibody ratio compared with LbAg-vaccinated and non-vaccinated animals. The association of TGF-beta with enhanced susceptibility to infection was confirmed in mice co-vaccinated with LaAg and neutralizing anti-TGF-beta antibodies. Upon parasite challenge, these animals developed much smaller lesion sizes and parasite burdens, comparable with non-vaccinated controls. The disease-promoting effect of LaAg vaccination is not a general event, as in contrast to BALB/c, the disease outcome in C57Bl/6 mice was unaltered. Together, these findings indicate that species-specific components of L. amazonensis activate overt TGF-beta production that predisposes more susceptible individuals to aggravated disease following vaccination. 相似文献
90.
Correia H González-Paramás A Amaral MT Santos-Buelga C Batista MT 《Phytochemical analysis : PCA》2005,16(5):380-387
The antioxidant activity of an aqueous extract (infusion) and respective ethyl acetate fraction of Equisetum telmateia Ehrh. (Equisetaceae), a plant used in traditional medicine for its anti-inflammatory and diuretic properties, has been evaluated by DPPH, TEAC and TBARS assays. A high and significant antioxidant activity was detected in the ethyl acetate fraction. Analysis of the aqueous extract and the ethyl acetate fraction by HPLC-PAD-ESI/MS allowed the identification of the major phenolic compounds as flavan-3-ol, kaempferol and phenolic acid derivatives. Among the flavan-3-ols, A-type proanthocyanidins and afzelechin derivatives were detected as well as the more common B-type procyanidins, B2 and C1, whose identification was further confirmed by HPLC using detection involving chemical reaction with p-dimethylamino-cinnamaldehyde. The results suggest that the anti-inflammatory activity of E. telmateia could be due, at least in part, to the presence of compounds with antioxidant activity. 相似文献